import sys
from  PyQt5.QtCore import Qt
from PyQt5.QtWidgets import QWidget,QLCDNumber,QSlider,QVBoxLayout,QApplication

class Example(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        lcd=QLCDNumber(self)
        sld=QSlider(Qt.Horizontal,self)

        vbox=QVBoxLayout()
        vbox.addWidget(lcd)
        vbox.addWidget(sld)

        self.setLayout(vbox)
        sld.valueChanged.connect(lcd.display)

        self.setGeometry(300,300,250,150)
        self.setWindowTitle('Signal & slot')
        self.show()

if __name__=='__main__':
    app=QApplication(sys.argv)
    ex=Example()
    sys.exit(app.exec_())

